Graphene-multi walled carbon nanotube hybrid electrocatalyst support material for direct methanol fuel cell

Nanostructured PtRu and Pt dispersed functionalized graphene–functionalized multi walled carbon nanotubes (PtRu/(f-G–f-MWNT)), (Pt/(f-G–f-MWNT)) nanocomposites have been prepared. Electrochemical studies have been performed for the methanol oxidation using cyclic voltammetry (CV) and chronoamperometry technique. Full cell measurements have been performed using PtRu nanoparticles dispersed on the mixture of functionalized graphene (f-G) and functionalized multi walled carbon nanotubes (f-MWNT) in different ratios as anode electrocatalyst for methanol oxidation and Pt/f-MWNT as cathode catalyst for oxygen reduction reaction in direct methanol fuel cell (DMFC). In addition, full cell measurements have been performed with PtRu/(50 wt% f-MWNT + 50 wt% f-G) and Pt/(50 wt% f-MWNT + 50 wt% f-G) as anode and cathode electrocatalyst respectively. With PtRu/(50 wt% f-MWNT + 50 wt% f-G) as anode electrocatalyst, a high power density of about 40 mW/cm2 has been obtained, in accordance with cyclic voltammetry studies. Further enhancement in the power density of about 68 mW/cm2 has been observed with PtRu/(50 wt% f-MWNT + 50 wt% f-G) and Pt/(50 wt% f-MWNT + 50 wt% f-G) as electrocatalyst at anode and cathode respectively. These results have been discussed based on the change in the morphology of the f-G sheets due to the addition of f-MWNT.